San Francisco, CA (Sports Network) - Chris Johnson ran for 135 yards and scored twice, as Tennessee got back to its winning ways in a 34-27 triumph over San Francisco.

Johnson, the league's leading rusher coming into Week 9, pushed his total to 959 yards on the year coming off a franchise-record 228-yard, two-score performance against the Jaguars last week.

Vince Young, making his second start of the season after replacing Kerry Collins in Week 8, led the Titans (2-6) to their second win in as many weeks after a dismal 0-6 start. The former Texas standout ran for a touchdown and threw for 172 yards on 12-of-19 passing.

"You can say we're proud of each other as an offense, as a team," Young said. "At the same time, I just want to take it a game at a time, and show my coaches that the year off -- what I've been doing is concentrating and paying attention to everything that's being said."

Justin Gage caught four passes for 97 yards, while the defense again showed some bite, logging four sacks, three interceptions and two forced fumbles.

Cortland Finnegan's 39-yard interception return for a touchdown with just under three minutes to play ultimately served as the game-winning score after a 49ers hurry-up offense found the end zone inside the final minute.

San Francisco also made a switch under center last week, opting to start former No. 1 draft pick Alex Smith, who took over for Shaun Hill on a full- time basis in last week's close loss to the undefeated Colts.

"We have a formula in terms of how we play and how we win games," 49ers head coach Mike Singletary said. "The number one thing is we cannot turn the ball over. That's the thing that basically killed us today."

Smith was solid in the early going, but two of his three picks came over the final 6 1/2 minutes to derail any hope of a comeback. He finished 29-of-45 for 286 yards and two touchdowns to Jason Hill. Smith also fumbled twice, losing one.

Frank Gore scored on the ground with 83 yards on 15 rushes and caught seven passes for 75 yards. Vernon Davis nabbed 10 balls for 102 yards for the 49ers (3-5), who have dropped four in a row since a solid 3-1 start.

With the game tied at 17 late in the third quarter, San Francisco took nearly 10 minutes off the clock on a 15-play, 66-yard odyssey that ended with a Joe Nedney 25-yard field goal four minutes into the final period.

Two plays into Tennessee's ensuing drive, Johnson shot up the left sideline 81 yards to the end zone for what looked to be the go-ahead score. Replays confirmed that Johnson's foot came down out of bounds at the San Francisco 40, though.

Young moved things along with a 33-yard completion to a leaping Gage down the middle of the field, then scrambled for six yards to the five. Two plays netted five yards to bring up 4th-and-1 from the two.

Johnson took a handoff left, reached the sideline where he juked a tackler to the ground before slipping upfield and angling inside the pylon for a 24-20 lead approaching seven minutes to play.

Safety Chris Hope leaped in front of a Smith pass on San Francisco's second play from scrimmage and turned things back over to Young and the offense at the hosts' 39-yard line. Rob Bironas turned the play into a seven-point Titans lead on a 28-yard field goal.

San Francisco didn't get a chance to respond as Smith had his next pass tipped and taken 39 yards the other way by Finnegan for a 34-20 margin with 2:51 to play.

Smith then took the offense 78 yards in 11 plays and hit Hill for a three-yard score at the goal line to make it a one-score game -- with only 39 seconds to go -- but Tennessee recovered an onsides kick to seal the victory.

Nedney and Bironas traded field goals in the opening quarter before Rod Hood ran Smith's first interception back 43 yards to the 49ers' 24. Young turned that into a seven-yard rushing score a short time later for a 10-3 lead two minutes into the second.

The hosts immediately put together a drive to tie the game at 10 as Smith connected with Davis for 40 yards to reach the red zone and Gore punched it in from three yards out.

San Francisco owned a 17-10 edge at halftime after Smith directed a quick nine-play, 82-yard drive that ended with a 12-yard TD strike to Hill with 20 seconds on the clock.

Smith lost a fumble shortly into the third which the Titans turned into a game-tying TD. Keith Bulluck recovered on the 49ers' 36-yard line and Johnson had it in the end zone in short order for a one-yard score.

Game Notes

Hill had four catches for 50 yards while Michael Crabtree hauled in three passes for 30 yards in the loss...Michael Griffin and Finnegan led the Titans with seven tackles each. Hood had an interception for the second consecutive week...Patrick Willis headed the 49er defense with six stops...San Francisco has a 7-5 lead in its all-time series with Tennessee, and was a 33-22 road loser when the clubs last met in 2005.